There are statistics to support both sides, and some that show no difference at all. So why are they even used other than to generate revenue for both the city and producer of the system?
I have to disagree about red light cameras. When they installed them in Sacramento people actually stopped running red lights and it became safer for all of us. Prior to that you would often have to sit through a green light because so many people ran the red. I know one girl who got two red light tickets on the same day and she deserved both of them. She thought it was unfair but admitted that she ran the light both times. On the other hand, big brother is watching us in so many ways that I wouldn't be surprised if these cameras are watching us to.
I never thought much about it myself until I happened to read a few articles. It's insane to read about all of these instances where it is alleged that these "timings" have been deliberately tampered with in order to shorten the times and increase the number of occurrences. The system may be electronic, but what we have to remember is that it was created by a man. Men are not only fallible. They are corruptible.
Seriously. Statistics have been produced by both sides of the spectrum either celebrating the use of the cameras or condemning them as nothing more than a revenue tool. I for one believe it nothing more than a tool for revenue for both the company that produced the camera and the city in which the camera is used. There is also the issue of the cameras themselves taking inaccurate photos and videos. In some cases the timing of the "yellow to red" light itself has been tampered with to boost the number of occurrences per traffic light infractions. The city of Chattanooga, TN for example is currently involved in a lawsuit for this very matter.
First link: About five pages into it. Very interesting. I never thought about the relations to reaction times, judgment, and yellow light times of all things. It makes sense; both the reasoning behind reduced accidents with increased yellow light times as well as why the beneficiaries of red light camera revenue like to reduce the yellow light times.